Grip-pulley.



- Y P ATBNTED 00120, 1903.-. s. R. BATsoN. GRIP PULLEY.

APPLICATION IILD SEPT. 22. 1902.

.No MODEL.

UNITED STATES Patented October 20, 1903.

SAMUEL R. BArsoN, or PENGE, ENGLAND.

GRIP-PULLEY.

SPECIFICATION forming part of Letters Patent No. 741,614, dated October20, 1903. Application filed September Z2, 1902. Serial No. 124,446. (Nomndel.)

To all whom it may concern:

Be it known that I, SAMUEL ROBERT BAT- SON, a citizen of England,residing at No. 76 Wordsworth road, Penge, in the county of Surrey,England, have invented a certain new and useful Im proved Grip-Pulley,(for which I have made application for a patent in Great Britain, No.4,854, dated February 26, 1902,) of which the following is aspecification.

My invention relates to an improved construction of that kind of pulleyfor transmitting and receiving power by ropes, cords, or belts in whicha-grip is exerted automatically upon the rope, cord, or belt `by meansof movable jaws as it passes-onto the pulley, so as to eectually preventit from slipping. In such pulleys as heretofore proposed the said. jawshave always been held in the open position for receiving the rope bymeans of spring or wedge action, the pressure of the rope upon thebottom of the said jaws being made to press them inward, so as to gripthe rope, while compressing or putting tension upon the spring action.

My present invention has for its object a simplified construction ofksuch grip-pulleys whereby the use of springs or spring or wedge actionis entirely dispensed with, and thus the liability of the pulleysgetting out of order by the spring or wedge action becoming defective isavoided.

The essential features of the invention consist in constructing thegripping-jaws with inclines on their outer ends so formed that when therope in passing onto the pulley comes in contact with the said inclinesit first forces these, and consequently the outer ends of the jaws,apart until it can enter between concave surfaces of the jaws, whereuponin pressing against the inner or bottom parts of these it causes them toturn on their fulcra, so as to grip the rope between them. The fulcra ofthe jaws are constitutedr by rounded fillets formed on the outer sidesthereof, which fit into corresponding grooves formed in separate sidecheeks or disks of the pulley, as will be presently described.

Figure 1 of the accompanying drawings shows a side view, partly insection, of a grippulley constructed according to my invention.

Fig. 2 shows an endview, partly in section, showing the rope just aboutto enter between the gripping-jaws. Fig. 3 shows a part section,showingthe rope between the grippingjaws. Fig. 4 shows one of thegripping-jaws detached. y

The pulley consists of a central circular plate A, (which is preferablymade in two parts, as shown,for facilitating manufacture,) and twoseparate circular plates B, forming the side cheeks, suitably fixed to Aby screws or other fastenings, are of substantially the same diameter asthe central plate A. The circular plate A, has first, a peripheralgroove ct, and, secondly, in the side walls of this groove are formedrectangular recesses C C, into which fit the gripping-jaws D, the outersurfaces of which are of the angular form shown at Fig. 4, while theinner surfaces are formed, l

first, with an incline d, and, secondly, with a concave surface d',adapted to tit the sides of the rope or cord G. At the angle of theouter surfaces is formed a projecting rounded fillet d2, which when thejaws are fitted in their notches C and the side cheeks B are fixed onengages with acorresponding groove b, formed in the inner surfaces ofthe cheek, and thus constitutes the fulcrum on `which the jaw D turnsand also serves to secure the jaw in position on the pulley.

Assuming that the rope G is passing over the top of the pulley fromright to left, it is obvious that as the wheel rotates approximatelyonly those jaws at the right, top, and left of the pulleythat is to say,about twothirds of their total number-will be engaged in gripping therope, and as any pair of the jaws comes to that point on the left sideof the pulley where the rope no longer bears upon the pulley the ropewill exercise an outward pressure upon the concaved surfaces d of thatpair of jaws, causing them to open and release the rope. Thepreponderance of weight will then draw `the inner ends of thegripping-jaws D outwardly as the pulley rotates and the outer endstoward the cheeks B, thereby turning the jaws upon their fillets cl2 andcausing them to open wide.

These jaws remain open until the;T have passed to that point where therope can exercise pressure upon the pulley. At this point the rope willeither freely enter past rool the outer inclined surfaces d if the jawsY have remained open, or if they have shown a tendency to close, asshown in Fig. 2, the rope G will bear upon their outer inclined surfacesd and will first force these parts of the two jaws apart until the spacebetween them is suficient to allow the rope to enter between theconcaved surfaces d', as shown at Fig. 3. As by the above-describedmotion of the jaws the inner or lower ends thereof will have been raisedup from the bottom of the groove a, it will be seen that when the ropewhile in the position shown at Fig. 3 exerts an inward or downwardpressure upon such ends it will cause the concave surfaces d to exercisea gripping action upon the rope the force of which will be proportionateto the tractional force exerted on the leading side of the rope orcord., such grip being in all cases suflcient to elfectually prevent anyslipping of the rope or cord on the pulley. As soon as by the rotationof the pulley the inward pressure of the rope upon a particular jawisrelieved as the rope moves away therefrom the jaw will turn backward, soas to leave the rope free to pass away.

Having thus particularly described the nature of my said invention andthe best means I know of carrying the same into practical effeet, Iclaim-` A pulley comprising a central circular plate, a circular platesecured to each side of said central plate, said central plate providedwith a peripheral groove having the walls thereof alternately cut awayto form recesses, each of said side plates having its inner faceprovided with an annular groove semicylindrical in cross-section, saidgrooves adapted to have the lower portionsof their walls register withthe outer edge of the bottorn of the said recesses, said side plates ofsuch diameter that when set up they are adapted to form one wall of saidrecesses, and a gripping-jaw mounted in each of said recesses, saidgripping-jaws substantially in the form of bell-crank levers andprovided at theirangles with semicylindrical fillets adapted to engagein said grooves thus constituting a fulcrum for said jaws, and said jawswhen in their inoperative position at .the top further adapted to havetheir inner ends engage the bottom wall of said peripheral groove andwhen in their operative position to be free of the bottom Wall of saidperipheral groove, substantially as described.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witncsses.

S. R. BATSON.

Witnesses JOSEPH MILLARD, EDWARD GARDNER.

